International Space Station Status Report #99-48
2 p.m. CST, Thursday, December 9, 1999|
Mission Control Center, Houston, Texas
The International Space Station’s first two components are in good shape with only minor issues facing the flight control teams in Houston and Moscow - none of which affect the operation of the complex. Since raising the altitude of the Station last week, controllers continue to manage electrical power generated by the Zarya module. A Zarya software patch was uplinked yesterday from Russia’s Mission Control Center. This update allows 68 additional electrical power system parameters to be sent to the ground via Unity’s early communications system. This data now can be viewed more frequently using NASA’s Tracking and Data Relay Satellite System.
Late last week, Zarya’s automatic docking system, called KURS, was tested and showed discrepancies in its alternate system's relative velocity readings seen on the ground. Russian flight controllers plan to re-run the test in an attempt to determine if "noisy" interference from the Station's other systems is the culprit. KURS is used during the final rendezvous and docking of the ISS with the Zvezda service module.
After operating without problem for a week and a half, battery 1 telemetry showed the unit no longer discharging properly as designed and it was removed from the electrical bus of the Zarya module. Four batteries remain available for electrical power to Station systems.
Battery "capacity restoration" is continuing with battery 4 completing its deep discharge yesterday. The remaining batteries will undergo the same procedure over the course of the next three to four weeks. Capacity restoration is a procedure conducted on each battery every six months to maximize the useful life of the batteries. Batteries 1 and 2 remain disconnected from the electrical bus.
Meanwhile, at the Baikonur Cosmodrome in Kazakhstan, Zvezda is undergoing final testing and is basically ready for launch. While awaiting the recommendations of the investigation team on the recent Proton failure, Zvezda will undergo some repeat testing on equipment with the time available.
Station managers will travel to Moscow in late January for the next General Designers Review and Joint Program Review to assess the readiness of the module for flight. The meeting also will determine the most probable launch date based on the recommendations of the Proton rocket failure investigation team. Its report to the Russian Aviation and Space Agency is due later this month.
Zvezda, the Russian word for Star, will serve as the early living quarters for crews housed on the station when the Shuttle is not present. It also will provide life support functions, and command and control capability for the complex.
The International Space Station continues to operate in excellent shape as it orbits the Earth at an altitude of 245 by 236 statute miles. Since the launch of Zarya in November 1998, the ISS has completed more than 5,995 orbits. Space Station viewing opportunities worldwide are available on the Internet at:
The next International Space Station status report will be issued Thursday, December 16. For further information, please contact the NASA Public Affairs Office at the Johnson Space Center, Houston, Texas, 281-483-5111.
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